A power interruption can stop a pump, reset a controller and interrupt communication at the same time. Restoring power does not necessarily restore the process: a drive may be waiting for a new run command, a controller may need to complete its start-up sequence, or a pump protection condition may still be active.
Plan for two separate outcomes: how the equipment stops and recovers, and whether the process needs an alternative power source to continue operating.
Four Drive Functions That Are Often Confused
| Function | Purpose |
|---|---|
| Momentary power-loss recovery | Handles a brief interruption within the drive's configured limits. |
| Deceleration Energy Back (DEB) | Uses energy from the rotating load during controlled deceleration to support the DC bus temporarily. |
| Flying start or speed tracking | Allows a compatible drive to synchronise with an already rotating motor. |
| Automatic restart | Allows operation to resume under specified conditions after power returns or an eligible fault clears. |
These functions are different. Their availability and behaviour depend on the exact drive, settings and application. DEB does not provide sustained backup power, and flying start does not itself authorise a machine to restart.
Delta ME300 and MS300 documentation includes power-loss recovery, DEB and speed-tracking functions. Check the applicable manual rather than assuming they are enabled or suitable for every load.
Define What Should Happen When Power Returns
Decide whether the motor should remain stopped, wait for an operator or resume automatically once all conditions are satisfied. Check the run-command source, controller start-up sequence, interlocks and fault-reset behaviour together.
An unattended water system may need automatic recovery after supply stabilises and water availability is confirmed. Machinery accessible to people may require a deliberate restart. Automatic recovery must preserve the required safety functions and must not create unexpected movement.
Keep Pump Protection in the Recovery Sequence
Before restarting a pump, the system should confirm the conditions required for that installation, such as source water availability, reservoir demand and acceptable process pressure. Repeated reset attempts should not conceal a persistent fault.
Tell the supplier whether you use float switches, pressure transmitters, level sensors or a PLC, and how those signals interact with the drive. Our complete pump control system guide explains the component relationships.
Control Backup and Motor Backup Are Separate Requirements
A correctly sized UPS or DC backup system can keep selected controllers, instruments and communication equipment powered. That does not mean the pump motor has backup power. State which loads must remain energised and for how long.
If pumping must continue during a prolonged outage, assess an appropriately designed alternative supply. For water systems, compare solar pumping, generator supply and storage against the actual water duty. See our solar, grid and diesel comparison and UPS selection guide.
A Practical Planning Checklist
- Motor nameplate and existing drive or panel details.
- Supply voltage, phase and typical interruption duration.
- Which loads need backup and the required runtime.
- Required restart behaviour and existing protection signals.
- Application, installation environment and available alternative supply.
Contact Softcore Group Industrial Solutions with these details to source suitable drives, control-power equipment and panel components. Product compatibility, availability and lead time are confirmed before supply.
Technical Note
Model capabilities and ratings vary. Final selection, electrical design, protection, programming, installation and commissioning must be verified against the exact manufacturer documentation and site requirements.
Related catalogue examples: Delta Drives | Variable Speed Drives. For an equipment enquiry, contact Softcore Group Industrial Solutions at info@softcoregroup.co.za.
Technical Resources
Consult the Delta ME300 manual and Delta MS300 manual for model-specific functions. Schneider Electric also explains why automatic restart depends on control configuration and safe application conditions; its settings apply to the named Altivar models.